Television (TV) broadcasters have material concerns to ensure that the diverse aspects of digital TV transmissions are correct. For example, they have contractual obligations to the content providers that they carry, contractual obligations to advertisers, and regulatory obligations. Monitoring is required to audit these obligations to prove compliance or failure and to provide feedback to enable timely rectification of defects.
Many areas of TV signals are already addressed by standardised parametric monitoring (e.g. presence of sound within a prescribed range of loudness). However, there are many facets of TV signals that are not amenable to parametric monitoring, particularly interactive television.
Interactive applications rely on data from different systems and can have subtle failure modes. The nature of interactive applications is that their correct operation can only be determined by interacting with and exploring the application. Some interactive applications may have behaviours that cannot be tested by a single receiver. E.g. an application may be required to have different behaviour on high definition (HD) and standard definition (SD) receivers. Some applications may be different in subtle ways between TV services. E.g. there may be regional differences in contact details. Human operators may not be able to reliably validate these differences.
In a multichannel TV environment; due to the above, reliably monitoring interactive applications presents major problems for equipment logistics and man power.
Currently, the approach used to test interactive applications, in particular, is to have people paid to watch TV screens and press the interactive button at appropriate times, to check that functionality is working correctly.